Introduction
Ahead of every winter, Delhi-NCR's air quality becomes a national concern, and this year the National Highways Authority of India (NHAI) has been pressed into the response in a visible way. For dust control on the highways and expressways of Delhi-NCR, NHAI has deployed about 60 water-sprinkling tankers and sprinklers, 14 anti-smog guns, 23 mechanical road sweeping machines (MRSMs), two tractor-mounted broomers and more than 900 personnel; 13 MRSMs are operating across 157 km of national highway stretches in NCR (PIB, 22 October 2026).
The deployment matters for a reason beyond optics. The comprehensive source-apportionment study of Delhi's air pollution by IIT Kanpur (2016), commissioned by the Delhi government, estimated that road dust accounts for about 56% of the city's PM10 emission load and 38% of its PM2.5 emission load on an annual basis. Dust control on roads is therefore not a side activity for a highway agency; it is central to how the National Capital Region breathes. This article examines urban dust pollution as a Mains theme through the lens of institutional design and accountability.
Why Urban Dust Matters
- Re-suspension: Vehicles continuously lift settled road and soil dust back into the air. The IIT Kanpur study found that dust emissions from paved and unpaved roads vary with the "silt loading" on the surface and the weight of traffic, which is why sweeping and sprinkling target the silt, not just visible dirt.
- Coarse versus fine particles: Road dust dominates the coarse fraction (PM10) more than the fine fraction (PM2.5). Both harm health, but they call for partly different controls.
- Seasonality: In winter, Delhi's ambient PM2.5 and PM10 are driven more by secondary particles, vehicles and biomass burning; dust's relative role is larger in summer. Dust control is necessary but not sufficient for clean winter air - a fact that exam answers should acknowledge honestly.
The Institutional Framework
- CAQM: The Commission for Air Quality Management in NCR and Adjoining Areas is a statutory body created by an Act of 2021. It issues binding directions (under Section 12 of the Act) that apply across Delhi and the adjoining districts of Haryana, Uttar Pradesh and Rajasthan, cutting across state boundaries that otherwise fragment pollution control.
- GRAP: The Graded Response Action Plan is CAQM's emergency-response ladder. Its current schedule (revised 29 September 2026) has four stages keyed to Delhi's AQI: Stage I 'Poor' (201-300), Stage II 'Very Poor' (301-400), Stage III 'Severe' (401-450) and Stage IV 'Severe +' (above 450). Stages are invoked in advance, on IMD/IITM forecasts, and each higher stage adds to the actions of the lower ones.
- Dust actions are written into GRAP: Stage II explicitly requires daily mechanical or vacuum sweeping and water sprinkling with dust suppressants on identified roads, and names the responsible agencies - municipal commissioners and the chief executives of road-owning and maintaining agencies. The NHAI review mirrors this template: covering of construction material, dust-free road surfaces and measures aligned to the applicable GRAP stage.
- The NCAP backdrop: The National Clean Air Programme (launched January 2019) set a revised target of up to 40% reduction in PM10 levels, or meeting the national standard of 60 micrograms per cubic metre, by 2025-26 in 131 identified cities. City action plans under NCAP explicitly target road and soil dust among the major urban sources.
The Accountability Dimension: What the NHAI Case Shows
- Named responsibility and daily reporting: Member (Technical) Alok Deepankar's review directed field units to ensure full deployment of equipment and manpower, daily mechanical sweeping, and daily progress reports backed by geo-tagged photographs. Measurable, dated, location-stamped reporting is the core of accountability here.
- Public-facing accountability: The review also pressed for prompt redressal of complaints received through the Green Delhi app and social media, linking enforcement to citizen feedback.
- From compliance to co-benefit: About 13.58 lakh tonnes of inert material from Delhi's landfill sites has been reused in the embankments of the UER-II and DND-Sohna corridors - a waste-to-wealth example that shrinks landfill mounds while building roads. NHAI also planted about 9.80 lakh saplings in NCR in FY 2025-26 against a target of 9.52 lakh, with a survival rate above 90%.
- Congestion as an emissions issue: Decongestion projects such as UER-II, the Dwarka Expressway, DND-Sohna and the Delhi-Dehradun Expressway reduce idling and stop-go traffic, attacking vehicular emissions alongside dust.
The Accountability Gaps
- Fragmented ownership: NHAI controls national highways; most urban roads belong to municipal bodies and state agencies. GRAP names dozens of implementing agencies, and the chain is only as strong as its weakest municipal link.
- Episodic, not systemic: Sprinklers and anti-smog guns suppress dust temporarily; they do not remove the silt source. GRAP action intensifies only when AQI crosses thresholds, so control is reactive by design.
- Limited public visibility: Geo-tagged daily reports are internal documents. Citizens cannot yet see whether the stretch near their home was swept today.
- Dated science: The most comprehensive public source-apportionment for Delhi is from 2013-14 (published 2016). Policy still leans on its percentages, which underlines the need for fresh, regular studies.
Way Forward
1. Year-round regimes: Move dust control from a pre-winter surge to a year-round schedule of mechanical sweeping, paved shoulders and greened verges, so silt never accumulates. 2. Public dashboards: Convert geo-tagged compliance reporting into public dashboards for every road-owning agency, replicating the NHAI template across NCR. 3. Source control at construction sites: Strict enforcement of covering of construction material and of Construction and Demolition Waste Management Rules at the point of generation. 4. Convergence with NCAP: Tie highway-agency action plans to NCAP city action plans and funding, so the 2025-26 PM10 targets and highway works reinforce each other. 5. Updated evidence: Commission fresh source-apportionment studies so that agency targets track current, not decade-old, pollution shares.
Mains Practice Question
Q. "Road dust is among the largest contributors to Delhi-NCR's particulate pollution, yet responsibility for its control is scattered across multiple agencies. Discuss the institutional and accountability challenges of managing urban dust pollution in India, with special reference to the role of infrastructure agencies, and suggest a way forward." (250 words, 15 marks)
Model answer outline
- Introduction: Winter air crisis in Delhi-NCR; road dust contributes about 56% of PM10 and 38% of PM2.5 emission load (IIT Kanpur, 2016); NHAI's 2026 deployment as the entry point.
- Main body: (1) Institutional framework - CAQM under the 2021 Act, four-stage GRAP keyed to AQI, NCAP targets; (2) Accountability instruments in the NHAI case - named responsibility, daily geo-tagged reporting, citizen complaint redressal, co-benefit works such as reuse of landfill inert material; (3) Gaps - fragmented road ownership, reactive threshold-based action, temporary suppression rather than removal, dated source data.
- Conclusion: Dust control must move from seasonal emergency response to year-round, publicly visible, source-level accountability, with infrastructure agencies treated as permanent partners in air-quality governance.
Sources
Limitations: the IIT Kanpur percentages are from 2013-14 data and remain the most cited public source-apportionment for Delhi
they should be presented as study estimates, not current real-time shares. All NHAI operational figures are from the single PIB release cited.